Application Of Derivatives

increasing on $(0, \infty)$.

increasing on $\left(0, \frac{\pi}{\mathrm{e}}\right)$, decreasing on $\left(\frac{\pi}{\mathrm{e}}, \infty\right)$.

decreasing on $(0, \infty)$.

decreasing on $\left(0, \frac{\pi}{\mathrm{e}}\right)$, increasing on $\left(\frac{\pi}{\mathrm{e}}, \infty\right)$